01_current.js

var PasteMessage = require('components/messages/paste'),
    React = require('react');

function render(Component, props, callback) {
  var element = React.createElement(Component, props),
      root = document.createElement('div');

  var component = React.render(element, root, function() {
    setTimeout(function() {
      callback(root.childNodes[0], component);
    });
  });
}

QUnit.module('Components.Messages.Paste');

QUnit.test('renders the tweet message element', function(assert) {
  var message = { body: 'Cool, cool cool cool.'};

  var done = assert.async();
  render(PasteMessage, { message: message }, function(node) {
    assert.hasSelector('.paste-message');
    assert.hasText(node, 'pre.pasted-content code', 'Cool, cool cool cool.');
    done();
  });
});

02_refactored.js

var PasteMessage = require('components/messages/paste'),
    React = require('react');

QUnit.module('Components.Messages.Paste');

QUnit.test('renders the tweet message element', function(assert) {
  var message = { body: 'Cool, cool cool cool.'};
  
  // this.renderComponent
  // this.render
  // whatevz
  assert.renderComponent(PasteMessage, { message: message }, function(node) {
    assert.hasSelector('.paste-message');
    assert.hasText(node, 'pre.pasted-content code', 'Cool, cool cool cool.');
  });
});